


For Science

by nishizono



Category: Sherlock (TV)
Genre: M/M
Language: English
Status: Completed
Published: 2010-09-26
Updated: 2010-09-26
Packaged: 2017-10-12 22:03:51
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,495
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/129598
Author URL: https://archiveofourown.org/users/nishizono/pseuds/nishizono
Summary: <blockquote class="userstuff">
              <p>The fact that he's stretched out on the settee and staring at the ceiling isn't unusual. The fact that he's naked, however, <em>is</em>.</p>
            </blockquote>





	For Science

**Author's Note:**

> **Disclaimer:** None of these characters are mine, nor am I being paid to play with them. All characters depicted in sexual situations are considered by the author to be over the age of eighteen, regardless of their age in the source material.

  
It's half ten on a Friday night when John trudges up the stairs to the sitting room and promptly drops the grocery bags he'd been holding.

"Hello John," Sherlock mumbles. The fact that he's stretched out on the settee and staring at the ceiling isn't unusual. The fact that he's naked, however, _is_.

John realizes he's staring and quickly turns away, shielding his face with his hand. "Sherlock, what the hell are you doing?"

"Trying to determine whether or not it's possible for a man who is inexperienced with anal sex to reach orgasm solely from being penetrated."

" _What_? Why?" John splutters, then closes his eyes so he can hold up both hands to stop Sherlock from speaking. "Never mind. I don't want to know. I'm not interested."

"Neither am I." Sherlock sounds distinctly unhappy. "Which means Alexandra Purdue is guilty after all."

John grits his teeth and tells himself that for once, he's not going to take the bait. Less than ten seconds later, however, he's crossing the room and flopping down into his armchair with a sigh. "Alright, fine, I'll play along. Who is Alexandra Purdue and why is she guilty?"

"Really John, you needn't worry yourself on my behalf."

"Sherlock."

Sherlock heaves a sigh as if he's doing John a favor instead of the other way around. "Alexandra Purdue has been accused of sexually assaulting and murdering her long-term boyfriend. She's admitted to performing anal sex on him for an extended period of time, but she maintains that it was consensual in nature. I was so certain she was innocent..."

John is sure he's missing something, but that's nothing new when it comes to conversations with Sherlock. And since it's probably best if he doesn't think about _why_ Sherlock arrived at the conclusion that he had to experiment with anal sex in their sitting room, he settles for asking, "So for some reason, the fact that you don't enjoy-- ah-- _that_ \-- means she's guilty?"

"Obviously," Sherlock drawls.

"Obviously," John repeats under his breath and rolls his eyes. "Sherlock, has it occurred to you that just because you're not enjoying it doesn't mean he didn't?"

"Of course that's occurred to me. I'm not arguing that he couldn't have enjoyed it, John," Sherlock snaps.

John pinches the bridge of his nose and closes his eyes. "Right, I forgot, all that matters is whether or not he could've had an orgasm-- you know what? I'm not having this conversation with you. It's late, I'm exhausted, and this is just-- no."

John dares a glance at Sherlock as he pushes to his feet.

Sherlock is watching him with what, for Sherlock, amounts to a pout.

"No," John says, and jabs a finger in Sherlock's direction. "Do you hear me? No. Whatever you're about to ask me: _no_."

"I'm only asking for your medical opinion, John," Sherlock replies in a tone that says, quite clearly, that John should count himself lucky to be consulted on such an important matter by the great Sherlock Holmes.

John closes his eyes and counts to five, and hopes that when he opens them again, he'll wake up in a world where the extent of his flatmate's insanity is severed heads in the refrigerator.

"Please, John."

That damn word. It gets him every time. He'd suspect Sherlock of using it just to manipulate him, but he knows how much it hurts Sherlock's pride to say it. So after a few seconds of silence, he opens his eyes and stares down at Sherlock, trying to ignore the fact that Sherlock is still naked (and it isn't that naked bodies bother him-- he's a doctor, after all-- but it's one thing to see them in exam rooms and quite another to see them stretched out so nonchalantly in the middle of his flat). Finally, he replies, "I honestly don't know."

Sherlock's face falls.

"I'm sorry," John apologizes. "I know there are plenty of men who enjoy anal sex, and I know prostate stimulation is supposed to enhance the experience, but I don't know whether or not someone who's never--"

"Prostate stimulation?" Sherlock interrupts, his brow furrowed.

John lets himself indulge in a little twinge of self-satisfaction. It's rare that he knows something Sherlock doesn't, and he can't help but to revel in it for a few seconds before asking, "Haven't you ever had a prostate examination?"

Sherlock's eyes narrow.

"Of course not; I don't know why I asked." John sighs. "The prostate gland is--"

"I _know_ what the prostate gland is, John, but I fail to understand why having it stimulated would make the rest of the experience worthwhile."

John shrugs and tucks his hands into the pockets of his trousers. "I wouldn't know; I don't exactly have firsthand experience with that sort of thing."

"You're lying," Sherlock replies in the same tone he would have used to say ' _it's raining_ ' or ' _you forgot the milk_ '.

"What?" John chokes out.

"You're lying," Sherlock repeats. "You always put your hands in your pockets when you're lying."

"That," John snaps, "is none of your business."

Sherlock just stares at him.

"I'm going to bed," John announces. "You stay here and--" he gestures vaguely at Sherlock's naked body "--figure something out."

He makes it all the way to the base of the stairs that lead up to his bedroom before his conscience gets the better of him and he pauses. And god, he can't believe he's even considering staying, but Sherlock's silence is making him feel guiltier than anything Sherlock could have said out loud. After a full minute of internal debate, he lets out a resigned groan and strides back across the room to stand beside the couch with his arms crossed and a glare on his face.

Sherlock beams up at him.

"I don't know what you expect me to do," John complains. "If you think I'm going to stand here and let you talk at me while you-- _that_ \-- then you really are--"

"I want you to help me," Sherlock interjects.

John freezes mid-sentence with his mouth open and his eyes wide.

"You're more experienced with this sort of thing than I am, you would have an easier time locating my prostate than I would, I trust you." Sherlock ticks his points off on his ridiculously long fingers. "And now that I consider it, I believe one of the problems I've been having is that I can predict my own movements. There's no sense of excitement or ambiguity."

John just shakes his head; he doesn't know how to respond to that. Were he dealing with anyone but Sherlock, he might suspect they were pulling his leg, but he knows better than to hope for miracles. And yet, he realizes, he's not actually saying no.

"You find me attractive, even if you've convinced yourself it's in a purely aesthetic way," Sherlock points out in that matter-of-fact tone of his.

"Fine," John blurts out, if for no other reason than to get Sherlock to shut up. "But--" he points at Sherlock again "--this is a one time thing, do you understand?"

Sherlock looks amused, but he nods and says, "I promise."

John buries his face in his hands and groans. He'll go through with it-- he always goes through with things once he's decided to do them-- but he really has no idea why, other than his apparent inability to deny Sherlock anything he asks for. Which is bloody frustrating.

When he lifts his head again, Sherlock has already shifted on the couch so that he's lying with his legs parted and his knees bent, and John can't help but to look. Sherlock's flaccid penis is nestled in his meticulously groomed pubic hair, and John does a literal double take when he sees what looks suspiciously like the base of a vibrator peeking out from between Sherlock's buttocks.

John feels his cheeks burn. He's never been uncomfortable with sex, just like he's never been uncomfortable with naked bodies, but somehow the combination of those two things with Sherlock Holmes makes him feel as nervous as a schoolboy looking at nude photos for the first time. And the idea that Sherlock has been lying there with a vibrator inside of him the entire time they've been talking does things to John's body that he's not at all proud of.

When he's sure he can speak without his voice breaking, John murmurs, "What do you need me to do?"

"Use this to penetrate me," Sherlock replies as he slides his fingers down between his legs and pushes them against the bottom of the vibrator. He does it with so much nonchalance it's almost obscene.

John chews on his bottom lip and briefly considers backing out, but not because the idea of fucking Sherlock with a vibrator is unappealing. Quite the opposite, actually, and that's something he's not ready to admit to himself, let alone to Sherlock, who will undoubtedly rip it into tiny, thoroughly analyzed shreds. But his pride won't let him run away, and leaving would say just as much about what he's feeling as staying would, so he nods and goes to sit on the edge of the coffee table.

They stare at each other until Sherlock reaches over to take John's hand, and leads it down between his thighs. The vibrator is slick with lube and warm from the heat of Sherlock's body, and god help him, John is getting hard just from thinking about what he's about to do. He leaves the vibrator switched off, for now, and manages to maintain eye contact with Sherlock as he pulls the vibrator out by a few inches and then pushes it inside again.

Sherlock winces.

"You know," John says, but it comes out thick and a little hoarse, so he swallows and tries again: "You know, there are easier ways to go about figuring this out. You could just ask around. Why put yourself through this if you're not enjoying it?"

"My own observations are the only ones I can trust," Sherlock replies, his voice strained. "Human beings tend to exaggerate the quality of their sex lives when discussing them with others."

John can't really argue that point, being guilty of some embellishment himself, so he just nods and withdraws the vibrator until only the tip is still inside. Once Sherlock seems to have relaxed a bit, John pushes back inside at what he hopes is the right angle to make the end of the vibrator graze Sherlock's prostate.

This time, Sherlock lets out a surprised little grunt and narrows his eyes.

"Prostate," John explains with a quiet laugh. But that little twitch of pleasure clearly isn't enough to make Sherlock enjoy himself, so John thinks for a moment before asking, "The point of this is to find out whether or not a man can come just from being penetrated, right?"

"Yes," Sherlock bites out. His eyes are closed and his brow is furrowed, and it's obvious his brain is still moving at a million miles per second.

"But you realize that in the real world-- in an _uncontrolled environment_ \-- there'd be more to it than this," John points out. He's a bit nervous about suggesting it because at least right now, with him just sitting there and mechanically working the vibrator in and out of Sherlock's arse, they can still call it an experiment. But to take it further, to touch each other the way they would if this was ' _real_ ' sex, would blur all sorts of lines. Still, he decided, in for a penny...

Before Sherlock can say anything-- interrogate, analyze, protest-- John leans down and kisses him. To his surprise, Sherlock doesn't seem all that shocked; he's still for a moment (cataloging, probably) and then he carefully returns the kiss. It isn't as awkward as John had expected it to be, but there's a hesitation in the way Sherlock moves that says he's not very experienced either. Oh, but he catches on quickly, and when John teases Sherlock's mouth open with the tip of his tongue, and slides the vibrator into Sherlock's body at the same time, he's rewarded with a quiet little gasp that makes his toes curl.

"Better?" John whispers against Sherlock's lips.

Sherlock nods and lifts his head as if seeking another kiss, which John gives him with more enthusiasm than is probably wise. When leaning over at such an awkward angle starts to bother John's back, he sinks to his knees beside the couch, and when he begins fucking Sherlock with slow, shallow thrusts of the vibrator and Sherlock _moans_ into his mouth, every thought he'd had about trying to keep some distance between them promptly disappears.

"John." Sherlock says his name in a gasp. "I think-- I think you may have been right."

John chuckles, and as much as he hates to look away from Sherlock's face, which is flushed with pleasure now instead of discomfort, he can't help but to glance down at Sherlock's cock, which is slowly hardening against his hip.

"You're staring," Sherlock breathes.

"Sorry," John replies, but he isn't actually sorry at all and he's sure Sherlock knows that.

Sherlock reaches up and grabs him by the back of the neck to pull him down into another kiss, and mumbles against his lips, "Harder."

Their next kiss borders on violent. The sounds Sherlock is making have John so on edge that it takes all of his self control not to rut up against the side of the couch like an animal. And it's insane, he thinks, that it's _Sherlock Holmes_ of all people-- his cynical, disinterested Sherlock-- who's making him feel this way.

"John," Sherlock moans as he breaks away to tip his head back and gasp for breath. He's visibly trembling from head to toe, and when he tries to throw an arm over his face, John grabs it and pins it above his head.

"No," John whispers. His voice is ragged with want, and he digs his fingernails into Sherlock's wrist. "I want to watch you."

Sherlock clamps his mouth closed, presumably to muffle the whimper that escapes through his nose instead, and arches his back away from the couch. His cheeks are flushed and his eyes are fever bright, and he's coming apart right there in John's hands. It's more than John can take.

" _Fuck_ , Sherlock," John curses as he drags the vibrator out of Sherlock's body and tosses it aside. Before Sherlock can protest, though, John replaces the toy with two fingers, and it only takes him a matter of seconds to find Sherlock's prostate.

Sherlock gives a startled cry and jerks his arm out of John's grasp. Afraid that he may have taken things too far, John pauses, then lets out a surprised grunt of his own when Sherlock grabs at his cock through his trousers. John uses his free hand to shove at his waistband, and then clutches at Sherlock's hair when Sherlock's warm fingers close around the rigid shaft of his prick.

"John, don't stop-- _John_ ," Sherlock chants, shoving himself down onto John's fingers. " _Please_ , John, don't--"

"Shhh," John whispers, forcing himself to pay attention to what his hands are doing even though Sherlock's is threatening to drive him mad. He pushes a third finger into Sherlock's body and groans when the tight muscles clamp down on his knuckles. All he can think about is how incredible Sherlock would feel on his cock, and the thought makes him drive his fingers into Sherlock a little harder than he means to.

Sherlock gasps and rocks his hips downward, obviously eager for more.

"Does it feel good?" John breathes as he bows his head to bite at the sharp line of Sherlock's jaw. His hips are jerking, thrusting into Sherlock's fist, and his fingers are moving in almost the same rhythm, and it's actually quite clumsy and awkward, and fucking _perfect_.

To John's surprise, as wound up as he is, it's actually Sherlock who comes first. John is fucking him hard with his fingers when Sherlock grabs his wrist to hold it in place and then _grinds_ against his knuckles. Everything about that, from the way Sherlock moves his hips to the desperate little mewling sound he makes when he does it, is so blindingly hot that John almost loses it right then. But he doesn't get a chance to think about his own orgasm before Sherlock's body is tensing, and Sherlock is clenching hard around his fingers, and Sherlock's prick is jerking completely untouched against his belly as he comes.

"Oh god," John groans, torn between watching Sherlock's face and closing his eyes to concentrate on the sound of Sherlock's ragged voice moaning his name. In the end, he doesn't have a choice, because Sherlock's eyes are wide open and staring up at him, and there's not a chance in hell that he'd be able to look away even if he wanted to.

It's not until Sherlock finally begins to relax that John is able to tear his gaze away, and when he does, he bows his head and squeezes his eyes shut. Sherlock's hand is still on his cock but it's stopped moving, so he carefully withdraws his fingers from Sherlock's body and covers Sherlock's hand with his own.

"John," Sherlock breathes as his fingers tighten around John's prick. "John, look at me."

John's eyes snap open, and having Sherlock staring up at him when he's so close to the edge is all it takes. They only get a few strokes in before he's coming, shaking so hard his teeth chatter as his cock surges in their hands and splatters the side of the couch with come. Sherlock watches him the entire time, and it's John who has to look away because it's just too much, too intense, too _everything_.

"Shhh," Sherlock whispers when John more or less collapses against him. Then he says, "There's semen in your hair."

John lets out a choked laugh.

They stay that way for what feels like ages, and John is half-dozing until he hears Sherlock's breathing finally even out. That's when it really starts to sink in: for all intents and purposes, they've just had proper sex together, and there's no way either of them can pretend it was just an experiment. John swallows the panic that rises up inside him and lifts his head to look down at Sherlock.

Sherlock's gaze is steady.

"So, uhm," John says. He's never been good at awkward silences, especially not with people he's just finished shagging, but he doesn't know how to fill that silence this time other than to ask, rather lamely, "So uh, does that mean your theory-- you know-- that she's innocent?"

At first, Sherlock just stares at him with a horrifyingly blank expression, but then something changes-- his eyes brighten a bit and John thinks maybe the corner of his lips twitch-- and he drawls, "Well technically, my theory was never really a theory to begin with. It was merely a hypothesis."

As usual, John isn't sure what Sherlock's on about, but the amused look on Sherlock's face is promising so he decides to delay his sexual identity crisis for the time being.

"And a hypothesis, according to the scientific method, cannot be called a theory until it has undergone rigorous testing."

John quirks an eyebrow and tries to look calmer than he feels. The truth is, his heart is pounding and his mind is reeling, and he feels like his entire, fragile little universe is being tipped on its side. He should be used to that feeling by now, he thinks, but Sherlock has always been good at finding new ways to shove him headlong into an adrenaline rush.

"I'm not sure that I've collected enough data to draw any concrete conclusions from this experiment," Sherlock announces. His fingers are creeping around to the back of John's neck and up into John's hair, like maybe if he moves slowly enough, John won't notice. "Besides, one of the variables was changed halfway through, and I'm sure that invalidates the results somehow."

"So what you're saying--" John draws out the syllables, pretending to be slow to catch on "--is that we'll have to repeat the experiment?"

Sherlock's almost-smile widens. "If all the participants are amenable to it, of course."

John stares down at Sherlock's face-- Sherlock's brilliant, impossible, aggravatingly beautiful face-- and thinks about all sorts of things. He thinks about the fact that he isn't, generally speaking, interested in men _or_ sociopaths. He thinks about how much it will irk him to admit that everyone was right about them from the start. And then he smiles.

"You left the milk by the door," Sherlock murmurs as he pulls John down so that their lips are touching.

"I have your debit card; I can get more later." John chuckles. "For now, there's science to be done."

Sherlock lets out a huff of laughter, and John muffles it with a kiss.


End file.
